Infrared Photosynthesis
Photosynthesis using light at wavelengths beyond ~700 nm — extending Earth’s canonical visible-light photosystems into the infrared. On Earth, some purple bacteria and certain cyanobacterial chlorophylls (d, f) already absorb out to ~750 nm; theoretical and laboratory work has pushed this further.
The astrobiological relevance is that M-dwarf host stars peak in the red/near-infrared, so habitable-zone planets around them would benefit from organisms whose pigments extend the photosynthesis-red-edge outward — making such planets more biologically productive than visible-light analogs would suggest, and yielding a shifted red-edge surface biosignature.
Vault appearances
- abscicon26 (May 2026): Rohan Shiradhonkar (Monday session) proposes IR-photosynthesis as a mechanism pushing the photosynthesis red edge outward and expanding exoplanet habitability around M dwarfs (src-abscicon26-media-tips-1-2026-05).